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澳大利亚西悉尼大学自然科学留学生作业范文：Tripuhyite and schafarzikite: two of the ultimate sinks for antimony in the natural environment
The Journal of Burraga Sciences
ABSTRACT
In this section you write a 100-word summary of your report.
In order to clarify the roles that secondary minerals may determine the extent of the dispersion of antimony in oxidising environments, syntheses and stability studies of the oxides schafarzikite, FeSb2O4, and tripuhyite, FeSbO4, have been undertaken. Solubilities in aqueous HNO3 were determined at 298.15 K and the data obtained used to calculate values of ΔGfө at the same temperature. The derived ΔGfө(s, 298.15 K) values for FeSb2O4 and FeSbO4 are –959.4 4.3 and –836.8 2.2 kJ mol–1, respectively. Results have been compared with electrochemically-derived data in the literature, extrapolated from 771-981 K. The present study has shown conclusively that whilst the mobility of Sb above the water table is limited by simple Sb(III) and Sb(V) oxides and stibiconite group minerals, depending upon the prevailing redox potential and pH an important ultimate sink for Sb in the supergene environment is tripuhyite.
Key words : tripuhyite, schafarzikite, stibiconte, antimony, iron.
为了澄清，次生矿物可确定在氧化环境中的锑的分散程度的作用，合成和氧化物的红锑铁矿，fesb2o4，稳定性研究和锑铁矿，fesbo4，已经进行了。在水溶液在298.15 K和溶解度数据确定了使用在同一温度计算值ΔGFө。派生的ΔGFө（S，298.15 K）为fesb2o4和fesbo4值–959.44.3和–836.82.2 kJ摩尔–1，分别。结果已被与电化学衍生的文献中的数据比较，推断771-981 K.本研究得到结论，在某人的水面以上的流动性是通过简单的Sb（Ⅲ）和有限的Sb（V）的氧化物和黄锑华族矿物，取决于当时的氧化还原电位和pH值对锑在表生环境的一个重要极限沉锑铁
关键词：锑铁矿，红锑铁矿，stibiconte，锑，铁。
1. INTRODUCTION
In this section provide a background to your project; details on Sunny Corner, mine sites, sulfide deposits, soil chemistry, water chemistry, supergene geochemistry, etc. Be sure to discuss the type of sulfide deposit at Sunny Corner. Any historical information you may be able to source including geological information. Use the last paragraph to state your aims; if you read the last paragraph of this Introduction it reads “in this work…”. You should start your last paragraph in this fashion.
Annual production of antimony (Sb) ranks it ninth of all metals mined for industrial applications (Krachler et al., 2001; Filella et al., 2002a). Sb is a toxic heavy metal and this has occasioned many studies aimed at understanding its solubility behaviour in surface waters and how it may be immobilised in the supergene zone. Comprehensive reviews by Filella et al. (2002a,b, 2003, 2009) and Filella and Williams (2010) have increased our understanding of the behaviour of antimony in the natural environment when it is present at low concentrations and how this relates to assessment of toxicity. Reports concerning Sb in contaminated sites (e.g., Ashley et al., 2003; Wilson et al., 2004; Wilson et al., 2010; Tserenpil and Liu, 2011; Wang et al., 2011) and potential remediation measures (e.g., Navarro and Algucil, 2002; Biswas et al., 2009; Wu et al., 2010; Xi et al., 2011) have emerged in the literature. Nevertheless, conflicting reports of the mobility of Sb in hydrological systems, especially those in oxidising near-surface environments, remain scattered through the literature with some authors claiming that Sb is mobile (Vink, 1996; Krupka and Serne, 2002), some the contrary (Wilson et al., 2004), and others noting that little is known about the matter (Filella et al, 2002a, b). In order to resolve this divergence of opinion, knowledge is required of secondary Sb-bearing phases that may serve to limit Sb solubility
Antimony usually exists in oxidation states -III, 0, III and V, and all are found in Nature. Upon oxidation near the Earth’s surface, oxidation states III and V dominate, but the geochemistry of Sb in the supergene environment, above the water table, is still not well understood. The confusion arises to a large degree from assessments of solubility of Sb when using Sb2O5(s) as a proxy for naturally occurring secondary Sb(V) minerals (Vink, 1996; Bookins, 1986). The phase does not occur naturally. Studies that address this issue have emerged only recently, and have highlighted the roles that salts of the Sb(OH)6– ion and members of the stibiconite group (MxSb2(O,OH)7) exert a considerable control (Filella et al., 2009), an observation echoed by others (Majzlan et al., 2011). Still, it remains apparent that other controls must be more significant than these.
In this work, syntheses and stability studies of the oxides schafarzikite, FeSb2O4, and tripuhyite, FeSbO4, were undertaken to derive ΔGfө(s, 298.15 K) values. These experimental values are compared to electrochemically-derived data in the literature, extrapolated from 771-981 K. The results of this study provide insights into the limited mobility of Sb in the natural environment. 在这项工作中，合成和氧化物的红锑铁矿，fesb2o4，稳定性研究和锑铁矿，fesbo4，进行了推导ΔGFө（S，298.15 K）值。这些实验值相比，电化学衍生的文献中的数据，从771-981 K。这项研究的结果提供洞察某人的有限的流动性，在自然环境中推断
2. MATERIALS AND METHODS
Only write about the methods you present in your results – if you have methods in this section that are not presented in the Results section, you will lose marks. Cut and discard the sections that are not relevant to your project.
2.1 Soil Sampling Locations
Where did you sample? Use maps, words, GPS co-ordinates to illustrate where you took your samples.
2.2 XRD
What type? Run time? Software?.
2.3 Water
How did you prepare your waters for digestion?
2.4 SEM
How did you prepare your samples for analysis?
2.5 Analytical techniques
Did you use the AAS? Which AAS (model, make, etc)? Did you calibrate the AAS (how)? Did you use duplicates or blind duplicates to test your accuracy?
2.3. Data analysis and modeling
Did you use any techniques to test the statistical significance of your data? Did you apply a model?
3. RESULTS AND DISCUSSION
Here you report all your results. The secret is to be clear and concise. As this is a manuscript for a journal, you can put all Tables and Figure at the very end!! If you scroll to the end, you will see some Tables and Figure in their correct place. Use ONE whole page for EACH Table and Figure.
3.1 Heavy metals in Sunny Corner discharge waters
Stibiconite group minerals are also known as pegmatitic accessories (c.f. stibiobetafite and stibiomicrolite, above) and romeite commonly occurs in pegmatites as well (Mason and Vitaliano, 1953; Anthony et al., 1990-2003; Brugger et al., 1997). However, in oxidized ores, they must crystallise from aqueous solution at ambient temperatures. It is thus pleasing that in conjunction with the work of Diemar et al. (2009) and earlier studies of stibiconite itself (Dehlinger and Glocker, 1927; Natta and Baccaredda 1933; Dihlström and Westgren, 1937; Baetsle and Huys, 1968; Abe, 1979, and references therein), the synthetic work reported here concerning stetefeldtite and bismutostibiconite completes the accumulation of reliable syntheses from aqueous solution of all members of the stibiconite group.
3.2 Secondary minerals
Following the 40 day equilibration with 0.195M HNO3 the tripuhyite remained insoluble (Table X.X). For the congruent dissolution of the mineral according to equation (X.1), the stability of tripuhyite at 298.15 K may be calculated with the relationship [Fe3+]TOT = [Sb5+]TOT.
3.3 Any other section you may want to include
Following the 40 day equilibration with 0.195M HNO3 the tripuhyite remained insoluble (Table X.X). For the congruent dissolution of the mineral according to equation (X.1), the stability of tripuhyite at 298.15 K may be calculated with the relationship [Fe3+]TOT = [Sb5+]TOT.
3.4 Relationships between minerals and waters
Following the 40 day equilibration with 0.195M HNO3 the tripuhyite remained insoluble (Table X.X). For the congruent dissolution of the mineral according to equation (X.1), the stability of tripuhyite at 298.15 K may be calculated with the relationship [Fe3+]TOT = [Sb5+]TOT.
4. #p#分页标题#e#CONCLUSIONS
What is the answer to the question (check you title/hypothesis)?
Tripuhyite has been shown to be the ultimate mineralogical “sink” for Sb in the oxidized, supergene environment at redox potentials higher than those that serve to stabilise schafarzikite. These findings build on the work of Diemar et al. (2009), who concluded that Sb was relatively immobile in the supergene zone. This conclusion is undoubtedly correct and the current study has identified other unsuspected phases that play a role in reducing the solubility of Sb.
ACKNOWLEDGEMENTS
We thank…Charlie Murphy for driving the Hilux. Prof Williams and Prof Leverett for insightful information….Wayne for the AAS work…
REFERENCES
Use this referencing style APA!
Abe, M. (1979) Synthetic inorganic ion-exchange materials. XX. Ion-exchange properties of crystalline antimonic(V) acid with alkaline earth metal ions. Bulletin of the Chemical Society of Japan, 52, 1386-1390.
Brugger, J., Gieré, R., Graeser, S. and Meisser, N. (1997) The crystal chemistry of romeite. Contributions http://www.ukassignment.org/ to Mineralogy and Petrology, 127, 136-146.
Filella, M., Williams, P.A. and Belzile, N. (2009) Antimony in the environment: knowns and unknowns. Environmental Chemistry, 6, 95-105.
Filella, M. and Williams, P.A. (2010) Antimony biomethylation in culture media revisited in the light of solubility and chemical speciation considerations. Environmental Toxicology, 25, 431-439.
Foord, E.E., Hlava, P.F., Fitzpatrick, J.J., Erd, R.C. and Hinton, R.W. (1991) Maxwellite and squawcreekite, two new minerals from the Black Range tin district, Catron County, New Mexico, U.S.A. Neues Jahrbuch für Mineralogie, Monatshefte, 363-384.
Gayer, K.H. and Garrett, A.B. (1952) The equilibria of antimonous oxide (rhombic)in dilute solutions of hydrochloric acid and sodium hydroxide at 25oC. Journal of the Amercian Chemical Society, 74, 2353-2354.
Natta, G. and Baccaredda, M. (1933) Tetrossido di antimonio e antimoniati. Struttura cristallina dell' antimoniato di antimonile (tetrossido di antimonio), suo isomorfismo con i piroantimoniati di piombo e di calcio ed esame röntgenografico delle ocre di antimonio (Cervantite, Stibiconite) e degli antimoniati idrati di calcio (Idroromeite) e di piombo (Bindheimite). Zeitschrift für Kristallographie, 85, 271-296.
Nordstrom, D.K., Alpers, C.N., Ptacek, C.J. and Blowes, D.W. (2000) Negative pH and extremely acidic mine waters from Iron Mountain, California. Environmental Science and Technology, 34, 254-258.
Orlandi, P. and Dini, A. (2004) Die Mineralien der Buca della Vena-Mine, Apuaner Berge, Toskana (Italien). Lapis, 1, 11-24.
Orosel, D., Balog, P., Liu, H., Qian, J. and Jansen, M. (2005) Sb2O4 at high pressures
and high temperatures. Journal of Solid State Chemistry, 178, 2602-2607.
Williams, P.A. (1990) Oxide Zone Geochemistry. Ellis Horwood, Chichester.
Captions of Tables
Put the captions for all your Tables on this page. The on the following pages have each Table on its own separate page.
Table 1. Pourbaix diagram displaying stability fields of schafarzikite and tripuhyite with respect to dissolved iron species, calculated at 298.15 K and total dissolved concentrations of Sb and Fe of 10–6 mol dm–3 (bold lines). Areas of predominance of dissolved Sb species are separated by dashed lines.
Table 2…
Table 3…
Table 1. Powder X-ray data for synthetic tripuhyite
h k l dobs/Å dcalc/Å
1 1 0 3.2786 3.2792
1 0 1 2.5625 2.5627
2 0 0 2.3185 2.3187
1 1 1 2.2425 2.2430
2 1 0 2.0735 2.0739
2 1 1 1.7193 1.7194
2 2 0 1.6395 1.6396
0 0 2 1.5376 1.5375
3 1 0 1.4665 1.4665
1 1 2 1.3920 1.3921
3 0 1 1.3813 1.3811
Captions of Figures
Put the captions for all your Figures on this page. The on the following pages have each Figure on its own separate page.
Figure 1. Pourbaix diagram displaying stability fields of schafarzikite and tripuhyite with respect to dissolved iron species, calculated at 298.15 K and total dissolved concentrations of Sb and Fe of 10–6 mol dm–3 (bold lines). Areas of predominance of dissolved Sb species are separated by dashed lines.
Figure 2…
Figure 3…
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